Cans filled with 19th century gold coins were found by a California couple. / AFP

by Marisol Bello, USA TODAY

by Marisol Bello, USA TODAY

For anyone wondering how much buried treasure is actually worth, the answer came on Tuesday night.

Three months after a California couple found a stash of rare, mint-condition 19th-century gold coins buried in their yard, some of the collection of more than 1,400 coins was auctioned off at the Old San Francisco Mint.

One of them - an 1874 $20 double eagle that is usually worth $4,250 - sold for $15,000, the Associated Press reported.

The coins, in denominations of $5, 10 and $20, are worth almost $28,000 in face value. But they are so rare and in such good condition, several individual pieces are expected to sell for as much as $1 million each. The entire collection is expected to fetch at least $10 million.

About 60 of the coins will be part of an exhibit at the Old Mint Building in downtown San Francisco. The proceeds from the auction of the 1874 $20 Double Eagle will go toward upkeep of the historic building.

The rest of the collection will go on sale on Amazon.com, where buyers can bid on individual pieces.

"This couple is so thankful and feeling so blessed, and they have been really looking forward to this day," Don Kagin, the Tiburon coin dealer handling the sale, told the San Francisco Chronicle. "It's a big day."

The Northern California couple's identify has not been revealed. The pair were walking their dog on their property when they noticed a canister jutting out of the ground. The property had a colorful history stretching back to the earliest days of the gold rush, so the couple often found tools and other items buried around the land, according to Kagin's website.

Using a stick, they pulled out the can. It was sealed and very heavy and it wasn't until the lid cracked off that they saw the edge of a gold coin. In total, they found eight cans buried near a tree. The coins dated from 1847 to 1890.

"Little did they know that they had made the greatest find of buried treasure in U.S. history," Kagin says on its website.

The find has fueled months of speculation, conspiracy theories, fortune hunters, tall tales and all around open-mouthed shock.

The Chronicle reports that some amateur historians say the coins were snatched by legendary gun slinger Jesse James, while others say they were stolen by stagecoach robber Black Bart.

Some claimers say their grandfathers, aunts or more distant relatives owned the coins â?? and they've demanded them back. One man journeyed to the Gold Rush-era town of Jackson where he's sure the coins were first buried, and said he'd found their original location at an ancestor's house. He threatened to sue.

One theory says the coins came from a 1901 theft by a mint worker and another says they are sacks of coins stolen by the city treasurer in 1898.

So far, no one's come forward with a legitimate version, federal officials say.